Acoustic characteristics of FeSe single crystals

Abstract

The results of the comprehensive ultrasonic research of high quality single\ncrystals of FeSe are presented. Absolute values of sound velocities and their\ntemperature dependences were measured; elastic constants and Debye temperature\nwere calculated. The elastic C11-C12 and C11 constants undergo significant\nsoftening under the structural tetra-ortho transformation. The significant\ninfluence of the superconducting transition on the velocity and attenuation of\nsound was revealed and the value of the superconducting energy gap was\nestimated.\n